Both the Maruyama and Solo bypass excess pressure from the pump back to the tank. I also consider the fact that when using one of these units, you are walking. To apply 1 gallon per 1000, I am walking around 2 MPH using an AI11004 tip set at 40 PSI. If I have the 3 nozzle boom, I am definitely moving. That set up is passing 1.2 GPM.